Various embodiments of the invention are directed to a portable power system with multiple power generation modes and mode based adjustable drag configuration. In particular, embodiments of the invention include a system with an adjustable inlet ram air inlet, a ram air powered section (e.g. a ram air powered turbine with an adjustable ram air inlet), a fuel powered section, e.g., jet fuel powered auxiliary power unit, which is used when insufficient ram air is present or a power surge requires augmented power generation, and a generator section selectively coupled with the ram air powered section and the fuel powered section.
A need exists to provide a mobile auxiliary power unit that can be selectively attached to mobile structures to provide on-demand power to another structure such as an aircraft. Systems or mobile structures can require additional power above and beyond what existing power generation systems can provide. Examples of a system that might require additional power are laser systems or other high power demand systems. Applications that can require such systems can include search and rescue, mobile mining systems, underwater systems, manufacturing systems, demolition systems, military systems, radio frequency systems, directed energy systems, firefighting systems, space systems, airborne systems, or land mobile systems as well as fixed structures.
One powered mode can include a system that uses a jet engine and integral fuel tank within an auxiliary power pod that hangs from an aircraft wing or hard point. Multiple drag adjustment systems can be used with various embodiments of the invention. For example, a ram air powered system can use an air path that enters through a variable inlet structure which adjusts its aperture(s) based on power demand/production needs via a wind turbine section that drives a power train which in turn drives a power generation section. As power demand declines, then the variable inlets close and thereby reduce drag and power production. The variable inlet section also closes, adjusts, or reduces its aperture size until sufficient ram airflow is present to begin powering the wind turbine section or the auxiliary power unit is activated and requires airflow through the pod or structure to operate. The auxiliary power unit is also connected to the power generation section through another power train section which then turns the generator section and thereby generates power when insufficient ram airflow occurs or a surge power requirement exists. In some embodiments, the pod is releasably attached to an exterior section of a mobile structure such as an aircraft pylon. A transmission or clutch section or system can be used to decouple the wind turbine and the auxiliary power unit to reduce or adjust drag or power required to turn the power generator section. Exterior sections of various embodiments can be formed to reduce external drag.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.